Lack of genetic isolation by distance, similar genetic structuring but different demographic histories in a fig-pollinating wasp mutualism

2015 ◽  
Vol 24 (23) ◽  
pp. 5976-5991 ◽  
Author(s):  
Enwei Tian ◽  
John D. Nason ◽  
Carlos A. Machado ◽  
Linna Zheng ◽  
Hui Yu ◽  
...  
Keyword(s):  
Isolation By Distance ◽  
Genetic Isolation ◽  
Genetic Structuring

scholarly journals Genetic population structure of the monogenean parasite Gyrodactylus thymalli and its host European grayling (Thymallus thymallus) in a large Norwegian lake

Hydrobiologia ◽  
2020 ◽  
Author(s):  
Ruben Alexander Pettersen ◽  
Claudia Junge ◽  
Kjartan Østbye ◽  
Tor Atle Mo ◽  
Leif Asbjørn Vøllestad
Keyword(s):  
Genetic Structure ◽  
Evolutionary Biology ◽  
Isolation By Distance ◽  
Genetic Structuring ◽  
Thymallus Thymallus ◽  
Homing Behavior ◽  
Genetic Population ◽  
Monogenean Parasite ◽  
European Grayling ◽  
Genetic Clusters

Abstract Understanding how populations are structured in space and time is a central question in evolutionary biology. Parasites and their hosts are assumed to evolve together, however, detailed understanding of mechanisms leading to genetic structuring of parasites and their hosts are lacking. As a parasite depends on its host, studying the genetic structure of both parasite and host can reveal important insights into these mechanisms. Here, genetic structure of the monogenean parasite Gyrodactylus thymalli and its host the European grayling (Thymallus thymallus) was investigated in 10 tributaries draining into the large Lake Mjøsa in Norway. The population genetic structure of spawning grayling was studied using microsatellite genotyping, while G. thymalli was studied by sequencing a mitochondrial DNA gene (dehydrogenase subunit 5). Two main genetic clusters were revealed in grayling, one cluster comprising grayling from the largest spawning population, while the remaining tributaries formed the second cluster. For both taxa, some genetic differentiation was observed among tributaries, but there was no clear isolation-by-distance signature. The structuring was stronger for the host than for the parasite. These results imply that moderate to high levels of gene flow occur among the sub-populations of both taxa. The high parasite exchange among tributaries could result from a lack of strong homing behavior in grayling as well as interactions among individual fish outside of the spawning season, leading to frequent mixing of both host and parasite.

Genetic isolation by distance in the yellowfin goby populations revealed by RAD sequencing

2019 ◽  
Vol 67 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Shotaro Hirase ◽  
Ayumi Tezuka ◽  
Atsushi J. Nagano ◽  
Kiyoshi Kikuchi ◽  
Wataru Iwasaki
Keyword(s):  
Isolation By Distance ◽  
Rad Sequencing ◽  
Genetic Isolation ◽  
Yellowfin Goby

Genetic subpopulation structuring and its implications in a mature eastern white pine stand

2005 ◽  
Vol 35 (5) ◽  
pp. 1041-1052 ◽  
Author(s):  
Samuel E Nijensohn ◽  
Paul G Schaberg ◽  
Gary J Hawley ◽  
Donald H DeHayes
Keyword(s):  
Genetic Similarity ◽  
Isolation By Distance ◽  
Hierarchical Cluster ◽  
Generation Gap ◽  
Tree Age ◽  
Specific Information ◽  
White Pine ◽  
Eastern White Pine ◽  
Genetic Structuring ◽  
Size Growth

We examined patterns of genetic structuring within a mature eastern white pine (Pinus strobus L.) forest, using geographic information system (GIS)-based data and maps that combined genetic (isozyme analysis of 46 loci) and other tree-specific information (e.g., size, growth, age, and location) for 220 trees in Jericho, Vermont. Interconnections between genotypic information with other tree characteristics revealed several patterns of genetic structuring. Average observed heterozygosity generally increased with tree age-class, and trees with a high number of rare alleles were disproportionally represented in suppressed crown classes. Spatial structuring was also evident: trees within 5 m of one another were highly related, and levels of relatedness generally decreased with increasing distance between trees. In general, a 35-m-radius circle around any tree circumscribed its zone of genetic similarity. Hierarchical cluster analysis indicated the stand consisted of five family groups that exhibited greater genetic similarity within than among clusters. Temporal structuring (a generation gap) was also evident: trees of similar age showed significant positive relatedness, as did trees 30–40 years apart. Patterns of genetic structuring likely resulted from the combined influences of natural selection, isolation by distance, and functional generation times. Genetic structuring may also have biological and management implications. Computer-based simulated harvests suggested that the stand could experience genetic alteration when tree removal criteria disrupted existing structural patterns.

Significant population genetic structuring but a lack of phylogeographic structuring in the endemic Tasmanian tree frog (Litoria burrowsae)

2014 ◽  
Vol 62 (3) ◽  
pp. 238 ◽  
Author(s):  
Z. Y. Zhang ◽  
S. Cashins ◽  
A. Philips ◽  
C. P. Burridge
Keyword(s):  
Population Genetic ◽  
Nuclear Dna ◽  
Isolation By Distance ◽  
Global Climate ◽  
Haplotype Diversity ◽  
Habitat Destruction ◽  
Phylogeographic Structure ◽  
Tree Frog ◽  
Genetic Structuring ◽  
Management Units

Conservation of frogs is of global concern, owing to declines resulting from habitat destruction, global climate change, and disease. Knowledge of genetic variation in frog species is therefore desirable for the identification of management units. Here we surveyed mitochondrial DNA sequence variation in the Tasmanian endemic hylid frog Litoria burrowsae, which is infected by chytrid fungus, Batrachochytrium dendrobatidis, and may be declining. Neither phylogeographic structure nor deep phylogenetic divergence was detected in the species, although its populations were highly differentiated with respect to haplotype frequencies. The low-haplotype diversity in L. burrowsae suggests a recent bottleneck in the species, and population genetic structuring may reflect isolation by distance as well as founder effects associated with range expansion. Three putative management units were identified that require verification based on nuclear DNA variation and adaptation to local environments.

Population structure in two geographically sympatric and congeneric ectoparasites (Cimex adjunctus and Cimex lectularius) in the North American Great Lakes region

2017 ◽  
Vol 95 (12) ◽  
pp. 901-907 ◽  
Author(s):  
Benoit Talbot ◽  
Maarten J. Vonhof ◽  
Hugh G. Broders ◽  
M. Brock Fenton ◽  
Nusha Keyghobadi
Keyword(s):  
Population Structure ◽  
Genetic Variation ◽  
Isolation By Distance ◽  
Spatial Genetic Structure ◽  
Geographic Area ◽  
Abundant Species ◽  
Cimex Lectularius ◽  
Genetic Structuring ◽  
The North ◽  
Genetic Clusters

Subdivided populations can be described by different models of population structure that reflect population organization, dynamics, and connectivity. We used genetic data to investigate population structure in two geographically sympatric, congeneric species of generalist ectoparasites of warm-blooded animals. We characterized the spatial genetic structure of the eastern bat bug (Cimex adjunctus Barber, 1939), an understudied and fairly abundant species, using microsatellite markers at a spatial scale representing contemporary dispersal of the species. We found seven genetic clusters, global [Formula: see text] of 0.2, 33% of genetic variation among sites, and nonsignificant isolation-by-distance. We compared these results with the common bed bug (Cimex lectularius L., 1758), a closely related but conversely well-known species, in the same geographic area. We found stronger genetic structuring in C. lectularius than in C. adjunctus, with 11 genetic clusters, [Formula: see text] of 0.7, 57% of genetic variation among sites, and significant but weak isolation-by-distance (R2 = 0.09). These results suggest that while both species can be described as having classic metapopulation structure, C. adjunctus leans more towards a patchy population and C. lectularius leans more towards a nonequilibrium metapopulation. The difference in population structure between these species may be attributable to differences in movement potential and extinction–colonization dynamics.

scholarly journals Genetic population structure constrains local adaptation in sticklebacks

2020 ◽  
Author(s):  
Petri Kemppainen ◽  
Zitong Li ◽  
Pasi Rastas ◽  
Ari Löytynoja ◽  
Bohao Fang ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Isolation By Distance ◽  
Regulatory Element ◽  
Morphological Data ◽  
Genetic Isolation ◽  
Genetic Population ◽  
Population Structuring ◽  
Different Populations ◽  
Trait Locus ◽  
Genomic Regions

AbstractRepeated and independent adaptation to specific environmental conditions from standing genetic variation is common. However, if genetic variation is limited, the evolution of similar locally adapted traits may be restricted to genetically different and potentially less optimal solutions, or prevented from happening altogether. Using a quantitative trait locus (QTL) mapping approach, we identified the genomic regions responsible for the repeated pelvic reduction (PR) in three crosses between nine-spined stickleback populations expressing full and reduced pelvic structures. In one cross, PR mapped to linkage group 7 (LG7) containing the gene Pitx1, known to control pelvic reduction also in the three-spined stickleback. In the two other crosses, PR was polygenic and attributed to ten novel QTL, of which 90% were unique to specific crosses. When screening the genomes from 27 different populations for deletions in the Pitx1 regulatory element, these were only found in the population in which PR mapped to LG7, even though the morphological data indicated large effect QTL for PR in several other populations as well. Consistent with the available theory and simulations parameterised on empirical data, we hypothesise that the observed variability in genetic architecture of PR is due to heterogeneity in the spatial distribution of standing genetic variation caused by strong population structuring and genetic isolation by distance in the sea.

scholarly journals Genetic structuring in Atlantic haddock contrasts with current management regimes

2020 ◽  
Author(s):  
Paul R Berg ◽  
Per E Jorde ◽  
Kevin A Glover ◽  
Geir Dahle ◽  
John B Taggart ◽  
...  
Keyword(s):  
Population Structure ◽  
North Atlantic ◽  
Isolation By Distance ◽  
Melanogrammus Aeglefinus ◽  
Genetic Structuring ◽  
Current Management ◽  
Northeast Atlantic ◽  
The North ◽  
Management Regime ◽  
The North Atlantic

Abstract The advent of novel genetic methods has made it possible to investigate population structure and connectivity in mobile marine fish species: knowledge of which is essential to ensure a sustainable fishery. Haddock (Melanogrammus aeglefinus) is a highly exploited marine teleost distributed along the coast and continental shelf on both sides of the North Atlantic Ocean. However, little is known about its population structure. Here, we present the first study using single-nucleotide polymorphism (SNP) markers to assess the genetic population structure of haddock at multiple geographic scales, from the trans-Atlantic to the local (fjord) level. Genotyping 138 SNP loci in 1329 individuals from 19 locations across the North Atlantic revealed three main genetic clusters, consisting of a Northwest Atlantic cluster, a Northeast Arctic cluster, and a Northeast Atlantic cluster. We also observed a genetically distinct fjord population and a pattern of isolation by distance in the Northeast Atlantic. Our results contrast with the current management regime for this species in the Northeast Atlantic, as we found structure within some management areas. The study adds to the growing recognition of population structuring in marine organisms in general, and fishes in particular, and is of clear relevance for the management of haddock in the Northeast Atlantic.

Dispersal patterns and population structure in a small marsupial, Antechinus agilis, from two forests analysed using microsatellite markers

2002 ◽  
Vol 50 (4) ◽  
pp. 325 ◽  
Author(s):  
F. J. L. Kraaijeveld-Smit ◽  
D. B. Lindenmayer ◽  
A. C. Taylor
Keyword(s):  
Population Structure ◽  
Isolation By Distance ◽  
Habitat Characteristics ◽  
Assignment Test ◽  
Dispersal Patterns ◽  
Genetic Structuring ◽  
Capture Site ◽  
Eastern Australia ◽  
Antechinus Agilis ◽  
One Year

Juvenile male agile antechinus (Antechinus agilis) are thought to disperse immediately after they leave the nest, whereas females are philopatric. However, no genetic data are available to support a hypothesis of male-biased dispersal, and the possible effects of habitat characteristics on dispersal are not known. We used five microsatellite loci to describe the dispersal patterns and population structure of A. agilis at two different forested sites (Mt Donna Buang and Mt Disappointment in central Victoria, south-eastern Australia). Within each site, DNA samples were collected from individuals from different trapping grids (four grids in Mt Donna Buang, collected over two years, and seven grids at Mt Disappointment, collected over one year). To assess levels of genetic structuring among the populations, Fst values (the proportion of genetic variance among populations) were calculated for each site and sex separately, and a test for isolation by distance was performed. Overall, Fst values were low, and did not increase with distance, and this may be the result of high levels of gene flow for both sexes at both sites, at least on the scale of less than 10 km. To investigate microsatellite patterns at a finer scale, we calculated pair-wise relatedness values separately for sites, years and sexes. By comparing these values for animals within and between grids, evidence was found for male-biased dispersal. A genetic assignment test provided further evidence for this: males were more likely to be assigned to grids other than their capture site. Most females had high assignment values for their capture site, although some of the females may have been immigrants. This result could be due to inaccuracies in the assignment test, or due to a higher frequency of dispersal of females than previously thought. The sex-biased dispersal was less pronounced at Mt Disappointment than at Mt Donna Buang. This may be related to the level of disturbance: logging patches, roads and fire-breaks (grass strips) disrupt the forest at Mt Disappointment more than at Mt Donna Buang.

scholarly journals Genealogy and phylogeography of Cyprinid fish Labeo rohita (Hamilton, 1822) inferred from ATPase 6 and 8 mitochondrial DNA gene analysis

2014 ◽  
Vol 60 (4) ◽  
pp. 460-471 ◽  
Author(s):  
Rupesh K. Luhariya ◽  
Kuldeep K. Lal ◽  
Rajeev K. Singh ◽  
Vindhya Mohindra ◽  
Arti Gupta ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Labeo Rohita ◽  
Isolation By Distance ◽  
Haplotype Diversity ◽  
Population Variation ◽  
Population Substructure ◽  
Distribution Analysis ◽  
Genetic Structuring ◽  
Potential Marker ◽  
Atpase 6

Abstract ATPase 6/8 gene (842 bp) of mitochondrial DNA was sequenced in Labeo rohita samples (n = 253) collected from nine rivers belonging to four river basins; Indus, Ganges, Brahmaputra and Mahanadi. Analysis revealed 44 haplotypes with high haplotype diversity (Hd) 0.694 and low nucleotide diversity (π) 0.001. The within population variation was larger (83.44%) than among population differences (16.56%). The mean FST value (0.166; P < 0.05) for overall populations revealed moderate level of genetic structuring in the wild L. rohita populations. The haplotype network presented a single clade for wild L. rohita population, from different rivers. Negative values for Fu’s index (FS), mismatch distribution analysis indicated period of expansion in L. rohita population. The time after recent expansion was estimated for each population, between 0.042 to 0.167 mya. The pattern of Isolation by Distance (IBD) was not significant (r = -0.113, P < 0.287), when all the sampling locations were compared (Mantel test), however, when an outlier (Indus, Brahmaputra and Mahanadi) was removed from the whole population set, a clear positive correlation between pairwise FST and geographic distance (Km) was seen. The analysis of data demonstrated that ATPase6/8 gene polymorphism is a potential marker to understand genetic population structure of wild L. rohita existing in different rivers. The study identified population substructure in wild L. rohita with common ancestral origin [Current Zoology 60 (4): 460–471, 2014].

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